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Environmental Health Impacts of Ethanol Production

The Good, The Bad, and Future Solutions

Felicia Wu, PhDDepartment of Environmental & Occupational Health

Graduate School of Public Health

University of Pittsburgh

Sigma Xi Chapter, University of Nebraska, 29 October 2008

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Presentation outline

Guiding questions:

How do environmental impacts of ethanol production & use compare with those of gasoline?

What solutions & alternatives exist?

Broad-based survey of ethanol & the environment

Current state of energy

Ethanol: background

Environmental impacts of corn-based ethanol production

Alternatives & potential solutions

Current state of energy: Global & US

Production

Demand increasing, supply decreasing

US energy use & imports

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Crude oil: Global production

Improved living standards worldwide increasing reliance on finite oil reserves for transportation, heating, industry “Finite” – new oil forms in geological time-scales

Total production mirrors total consumption: 30B bbls/yr At this rate, proved reserves will deplete in 40 years

McLaren 2008

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Crude oil: US trends

U.S. largest global user of oil energy (albeit efficiently)

Increasingly, we rely on imported crude oil

High % import from politically unstable regions

Security of future energy supply crucial policy issue

McLaren 2008

Gasoline prices increased dramatically since 1990s

Oil price affects agricultural production costs

2007: high petroleum costs affect US ag. expenditures (USDA 2008)

Petroleum fuel, fertilizers, chemicals, transportation, crop prices

Total cost % increase

from 2006

US farm production

expenditures (total)

$260 billion 9.3%

Per farm:

Fertilizer, lime, soil $8,070 26%

Feed $18,412 22%

Fuel $6,137 15%

Agricultural chemicals $4,832 12%

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… so US government looks to renewable fuels such as ethanol

“America is addicted to oil.” -President Bush, 2006 State of the Union Address

Background on ethanol

What is ethanol?

Ethanol production trends in US

Ethanol use in vehicles

US policies supportive of ethanol

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Ethanol: background

Pure alcohol, grain alcohol, drinking alcohol

Fermentation of sugar into ethanol “earliest organic reaction known to humanity”

Uses Consumption

Flavorings & scents

Medicines

Solvent in chemistry

FUEL (98% from corn)

2007

actual

2015

expected

2020

potential

Ethanol produced

(B gal)6.2 15.0 20.0

Corn yield (bu/A) 151 180 200

Corn produced

(Mbu)13,062 16,200 18,000

Corn used for

ethanol1670

(13%)

3866

(24%)

5150

(29%)

Corn available

for other uses

(Mbu)

11,392 12,334 12,850

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Corn-based ethanol production in U.S. (millions of gallons)

U.S. goal: 15 x 15 x 15 (yield, ethanol, 2015)

1 bu corn yields 2.7 gallons ethanol: 2.3B bu corn in 2007

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Existing & planned ethanol plants

Today: 134 existing plants; 77 under construction

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Ethanol doesn‟t replace gasoline…

… but complements it

Flex-fuel vehicles (FFV): 0-85% ethanol mixed with gasoline

E.g., E10 (10% ethanol, 90% gasoline), E85 ~7.3 million US cars in use compatible

with E85 (out of 65 million)

68% Americans didn‟t know they owned E85 FFV (2005 survey)

~13.7 million E85 FFVs in Brazil

Gasoline-powered cars can use E10

Ford Model T: Earliest FFV

Modern US postal FFV (E85)

Policy support for ethanol

2007 “20-in-10” initiative:

Reduce gasoline consumption by 20% in 10 years

Subsidies: $0.51/gal (now $0.45/gal) tax credit to refiners

Congressional mandates to produce:

4B gallons by 2006, 7.5B gallons by 2012

Recent legislation: 36B gallons by 2022

DOT: Fuel-economy compliance credits for new E85 vehicles

E.g., Chevy S-10 that gets 25 mpg counted for federal compliance purposes as if it gets 40 mpg

2007: Portland, OR: 1st city to require all gasoline sold within city limits contain ≥10% ethanol

Jan 2008: 3 states require ethanol blends: MO, MN, HI

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National Biofuels Action Plan (USDA/DOE)

Released Oct. 7, 2008

Interagency Biomass R&D Board focuses on 7 Action Areas:

Sustainability

Feedstock production

Feedstock logistics

Conversion science & technology

Distribution infrastructure

Blending

Environment, health & safety

Many of these areas have strong environmental component

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Environmental health impacts of corn-based ethanol production

Food supply

Air quality

Soil & water quality

Energy use

Carbon emissions

Animal feed quality

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Food vs. fuel debate

“Does corn ethanol compromise food supply?”

Not in US…

Most US corn production animal feed

Corn for human consumption: high-fructose corn syrup

5-10% increase in meat prices (Dale 2008)

…But possibly in poorer, corn-trading nations

Food corn same type as US animal feed

High food prices Feb 2007 Mexico riot over tortilla price

Food demand will double in 50 years (Tilman 2007)

Population increases to 9 billion & meat consumption increases

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Increased meat consumption in China & India

1 lb meat requires 10 lbs vegetable ~90% corn, 10% soybean meal

“Middle class” growing

Statistics: China: 1.33 billion people

India: 1.15 billion people

If each person ate 3 lbs more meat/yr, would need 67 billion lbs more corn 1.2 billion bushels

~10% of U.S. corn production

High all-around demand for corn will raise prices

Other factors also account for increased food prices

Higher fuel prices: increased

input & transportation costs

Increased food demand as

people in developing

countries improve diets

2 years of drought: poor

harvest in some world

regions

Food commodity prices rose >60%

in last 2 years. Index: Jan 1992 = 100.

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Air quality & health(excluding CO2)

Air pollution 7th-leading cause of death worldwide (WHO 2008)

Effects of ethanol (E85) vs. gasoline vehicles Ethanol use increases:

Ozone (2.14X as much as gasoline!)

Acetaldehyde

Formaldehyde

Ethanol use decreases: CO

NO2, SO2

Benzene

Butadiene

No significant change in particulate matter

If Los Angeles E85 vehicles (Jacobson 2007): 9% increase in ozone-related mortality! (asthma, bronchitis, heart attack)

No decrease in NO2, SO2, benzene / butadiene-related illness (e.g., leukemia)

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Soil & water quality

Soil overuse: erosion, nitrogen depletion

Water use 1 gal ethanol production requires 3-5 gal water

Problem for ethanol plants in arid locations

Irrigating new dedicated fields needs massive amounts of water

Water quality: runoff of pesticides and fertilizers >1000 kg nitrogen fertilizer / km2 corn into Mississippi

River (Schnoor 2008) Hypoxia in Gulf of Mexico: reduced O2 fewer fish, shrimp, crabs

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“Carbon neutrality” and biofuels

Main concern: Carbon dioxide‟s contribution to global warming

Carbon neutral: New Oxford American Dictionary‟s Word of the Year, 2006 Carbon emissions from fuel consumption offset by carbon

capture & sequestration (e.g., by planting crops)

Growing plants remove CO2 from air

Carbon in plants turned into biofuel (e.g., ethanol)

When biofuel combusted, CO2 released back into air

If made properly, biofuels can be carbon neutral

Per unit energy, ethanol trumps gasoline (Farrell et al. 2006)

Net fossil

input

Net fossil ratio Petroleum

input

GHG

emissions

MJfossil needed

for each

MJfuel

MJfuel made for

each MJfossil

input

MJpetroleum

needed for

each MJfuel

g CO2 emitted

per MJfuel

Gasoline 1.19 0.84 1.10 94

Corn

ethanol

0.77 1.30 0.04 77

Cellulosic

ethanol

0.10 10.0 0.08 11

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Biofuels & carbon debt:Land use change

Land in undisturbed ecosystems (esp. Americas & Asia) converted to:

Biofuel production

Food production, when agricultural land used for biofuel

Converting native habitats to cropland releases CO2 by burning plants & soils

~50 years: decay of leaves & roots further releases CO2

This is “carbon debt”

Over time, biofuels on converted land can repay carbon debts, if their greenhouse gas (GHG) emissions are less than GHG emissions of fossil fuels they displace.

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How many years for biofuels to repay carbon debt?

Ethanol production

type (Searchinger et

al. 2008)

# years of

increased

GHGs

Corn-based 167

Corn-based, improved

yield & tech34

Switchgrass-based (corn

land)52

Brazilian sugarcane

(tropical rain forest)45

Brazilian sugarcane

(grazing land)4

Ethanol production

type (Fargione et

al. 2008)

# years of

increased

GHGs

Corn-based (central

grassland)93

Corn-based

(abandoned land)48

Switchgrass-based

(marginal

cropland)

0

Brazilian sugarcane

(wooded land)17

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Ethanol production impacts on animal feed quality

Ethanol produced from corn Mycotoxins (toxins of fungal origin) concentrated up to 3X in co-products

90% co-products fed to livestock & poultry in animal feed

Usually as Dried Distillers Grains plus Solubles (DDGS)

What is the impact to animal health?

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Mycotoxins of concern in corn

Fumonisin Fusarium verticillioides, F. proliferatum

Aflatoxin Aspergillus flavus, A. parasiticus

Deoxynivalenol (DON,

vomitoxin)

F. graminearum, F. culmorum

Zearalenone F. graminearum, F. culmorum

Left to right:

Fusarium ear rot,

Gibberella ear rot,

Aspergillus ear rot

(photos: Gary Munkvold)

Multiple adverse animal health effects

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DDGS risk to animals

Impact to livestock industry ~$10 millions annually in reduced animal weight alone

(Wu F, Munkvold GP, J. Agric. Food Chem 56:3900-3911, 2008)

But not much economic incentive to change this

Ethanol plants want to sell DDGS to livestock producers…

10-20% revenues come from DDGS: $1.5 billion in 2006

Significant source of revenue for ethanol plants

… and livestock producers want to keep buying it

High corn price turn to cheaper feedstuffs

Currently, DDGS cheap: ~85% of cost of corn

Summary: Environmental impacts of corn ethanol, compared to gasoline

Food supply Both implicated in higher food prices:

Potential risk in poorer nations

Air quality Increased respiratory mortality & morbidity

Water use &

quality

Similar water use, risks to water quality from

increased runoff

Energy use Per unit improvement over gasoline

GHG emissions Over time, will result in lower emissions

Animal feed Potentially increased mycotoxin risk

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Corn growers already adopting environmental solutions…

No-till farming

Slows erosion, builds soil organic

matter

Advanced fertilizer technology

Improves crop nitrogen capture

Cover crops

Sequester soil carbon, intercept

nitrate & phosphorus runoff

Crop genetic improvements

Reduce pesticides & mycotoxins,

can increase stress tolerance &

nutrient efficiency

Beneficiaries:

Corn growers: lower input

costs

Ethanol plants: lower

grain costs

Environmental sectors:

reduced chemicals

reduced hypoxia & water

pollution, more efficient

land & water use

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Lignocellulosic ethanol:Introduction

“Lignocellulosic”: biomass composed of cellulose, hemi-

cellulose (carbohydrates), & lignin (cell wall component)

Can be converted to ethanol

Sources

Agricultural residues (e.g., corn stovers, wheat straw)

Dedicated energy crops: switchgrass, hybrid poplars (cottonwoods),

hybrid willows

Wood residues (e.g., sawmill & papermill discards)

Municipal paper waste

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Lignocellulosic ethanol production(Image source: DOE 2008)

Barriers to ethanol production

Sugars for fermentation trapped inside lignocellulose

High % of pentose vs. hexose in hemicellulose: difficult to ferment

Solutions

Pretreatment: open cell wall materials for enzymatic attack

Enzymatic hydrolysis (cellulase): converts cell walls to sugars

Fermentation: to convert sugars to ethanol engineered yeast to degrade pentose

Energy return on investment for ethanol

rE = ratio of energy in a gallon of ethanol to the

nonrenewable energy required to make it

rE = Eout / Ein,nonrenewable

rE always < 1 for nonrenewables like gasoline: at least some gross

energy input is lost when refining energy product

If rE > 1, we‟ve captured some renewable energy value

If rE > 0.76, it consumes less nonrenewable energy than gasoline

Meta-analysis of ethanol studies (Hammerschlag 2006):

0.84 ≤ rE ≤ 1.65 for corn-based ethanol

4.40 ≤ rE ≤ 6.61 for cellulosic ethanol

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Lignocellulosic ethanol: Promises

May 2008 Farm Bill: subsidies for cellulosic ethanol Refiners: $1.01 / gallon

Growers: $45 / ton of biomass

Potential environmental benefits: Can grow cellulosic crops on marginal lands

Reduces (doesn‟t completely solve) “food vs. fuel” dilemma

Perennial crops do not have high water / pesticide / fertilizer requirements

Reduces GHG emissions

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Lignocellulosic ethanol: Potential issues

Logistics: Harvesting, storage, preprocessing / grinding, transportation ~20% of current cost

What to do with co-products?

Animals can‟t eat wood / paper residues

Ethanol plants prefer to make profit from all parts of feedstocks

Even dedicated crops pose environmental concerns

Use of marginal land can destroy biodiversity

Some proposed crops are exotic or invasive: further threats to local biodiversity

“Food vs. fuel”: if profitable enough, may displace food crops

Win-win: Alternatives & potential technology / policy solutions

How to achieve environmental quality without

making any sector worse off? Solutions in:

Transgenic (genetically modified) crops

Alternative biofuels

Improved conversion processes

Other renewable energy sources

More energy-efficient lifestyles

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Transgenics: Bt corn & other crops

Bt corn can provide benefits in both starch & lignocellulosic feedstocks

Through reduced insect damage: Increase in yield

Increase in biomass

Reduction of mycotoxins more efficient conversion, healthier co-products for animal feed

Munkvold, Wu, Pometto, USDA Biotechnology Risk Assessment Grant (2008-2011)

Other transgenic possibilities: Stress-tolerant, drought-resistant crops to grow on marginal lands

Improved fuel conversion (e.g., more easily fermentable starch)

Photo: G Munkvold

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New biofuels

Butanol

Produced via fermenting biomass

Good energy density, but too costly to produce pure butanol

Mixed alcohols

Mixture of microorganisms digest biomass to acids

Acids converted into corresponding alcohols (ethanol, butanol, etc.)

Needs pH control & massive biomass in silage-like piles

Biogas (methane)

Generated by anaerobic conversion of waste residues

Methane combusted in furnace heat or steam

Useful if liquefied natural gas more common as transport fuel

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Syngas ethanol

New progress in thermochemical conversion processes through improved catalysis

Synthetic gas, “syngas,” can be converted to ethanol

Syngas (CO & H2) made by gasification of carbon-based materials

High temperature / pressure, oxygen-controlled atmosphere

DOE / Ames laboratory & ISU: develop nanotechnology-based catalyst to react with syngas to form ethanol

Avoids producing unwanted waste products

Advantages: can convert almost any carbon-based material to syngas (similar to feedstocks of cellulosic ethanol)

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Algae as biofuel source

“Algaculture”: farming algae for biofuels

Algae can be metabolically altered to generate high levels of oil ~6000 gal biofuel/A

Environmental benefits: Doesn‟t need freshwater, can use ocean or wastewater

DOE: If algal fuel replaced all petroleum fuel in US, would only require area equivalent to size of Maryland

Challenges: Containment, temp. control, high infrastructure costs

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“True renewables”: Wind and solar energy

Benefits

Wind & solar energy are

plentiful, renewable, widely

distributed, clean, & in theory

have zero GHG emissions

Current issues

Infrastructure costs

Siting & transmission lines

Windmills and Pickens‟ Plan

Could supply <20% US electricity

Could save US $300 billion annually in foreign oil

Could reduce GHG emissions (natural gas lower-polluting)

Issues: transmission lines expensive, natural gas still need for peak electricity demand

T. Boone Pickens (July „08)

Invest $1 trillion in wind turbine farms in Great Plains Wind Corridor

Turbines connect to power grid

Displaced natural gas can fuel vehicles

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More energy-efficient lifestyles

Our energy demands drove up price of oil…

Transport Fuel-efficient vehicles

Mass transit

Bicycling / walking

Buildings Use as much energy as transportation, release twice as much

greenhouse gas (Tilman 2007)

Natural lighting, compact fluorescents, turning off lights &

appliances, smaller homes (“Small House Society”)

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Summary

We can avoid a global energy crisis through renewable fuel sources

Ethanol has unique environmental health benefits & risks compared with gasoline

Technology & appropriate policies can make win-win situations for multiple sectors

Other renewable sources & lifestyle changes should be considered in conjunction with ethanol for energy-secure future

Final thoughts

Ethanol & climate change: well-

characterized

But ethanol & ozone-related mortality:

We need to pay more attention!

Many environmental solutions focus

on how to produce ethanol more

efficiently…

But how to reduce ozone pollution?

Focus technology $ and policy here

Get government agencies &

universities to “reach across the aisle”

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Acknowledgment

Donald Beermann: Sigma Xi President, University of Nebraska chapter

Gary Munkvold: Iowa State University

Paul Bertels, Geoff Cooper: National Corn Growers Association

Thomas Biksey, Judith Lave, George Leikauf, Yan Liu, Conrad Volz: University of Pittsburgh

Daniel Morris: General Dynamics